Saturday, May 31, 2014

Infra-Red Timelapse

Having had my Canon 50D converted to IR and knowing that the
50D can deliver Magic Lantern Silent (DNG) Pictures, ie via LV with no shutter
action, I thought I would carry out some experiments this weekend.

Unlike ‘normal’ photography, IR photography is best undertaken
in the brightest of bright sunshine, as we are capturing the reflected IR
photons from the sun. Thus there are three sweet times to take images, not two:
the golden hours of sunrise and sunset for ‘normal’ photography; and midday ‘golden
period’ for IR.

Until the heroes at Magic Lantern tweak the Silent Picture
mode, I’m a little limited to timelapses where the light doesn’t change drastically,
like is does at sunrise or sunset. Timelapses taken when the light is changing
by large amounts requires one to adopt the, so-called, holy grail technique;
where you intervene in the timelapse taking and make exposure (step) adjustments.

Magic Lantern offers another approach, whereby you use
Auto-ETTR. But, as the Silent (DNG) captured images currently don’t have any
exposure EXIF data, I am limiting myself to timelapse sequences where the light
is pretty much constant, ie I’m not using A-ETTR at the moment.